"For illustrative purposes, imagine an interaction between browser and site that goes something like this: Browser: I don’t allow cookies that store personally identifiable information that could be used to contact me without permission. Site: I do have some cookies to place here, but none do that. Browser: That sounds fine. Come on in."
The writer illustrates the situation out to the reader in a way that one can better understand it. They set it up as a relationship between the Browser and the site, offering an interesting perspective.